Furnace.



No. 726,298. x "PA'IBNTED APR.' 28, 1903. H. H.. HUFF.

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No. 726,298. PATBNTED APR. 23, 190s. i

H. H. HUET.

PURNAGE.

APPLIOATION Hmm Nov. 22, 1902. No nonni.. Q `c) a SH ETS-SHEET 2.

PATBNTBD'APR. 28,-1903.

H. H. Burr. PURNAGB; APPLIUATIOH FILED NOV. 22. 1902.

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LUNITED STATES Fernuni Ormes.

HENRY I-I. IIUFF, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO HUFF LOCO- MOTIVE APPLIANOE COMPANY, OF KITTERY, MAINE, Ay CORPORATION OF MAINE.

FURNACE.

SPECIFICATION forming' part of Letters Patent No. 726,298, dated April 2S, 1903..

Application filed November 22,1902. Serial No. 132,408. (No model.)

To @ZZ whom it may concern:

Be it known that I, HENRY H. I-IUFF, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Furnaces, of which the following is a specification. This invention relates to furnaces or fireboxes chieiiy for locomotive-engines,the doors of which are adapted to open inwardly and Io are so formed that when closed they will not eect a tight closure of the door-opening, but will admit a constant supply of air to promote combustion.

The present invention has for its object,

I5 first, to provide improved means for operating a door of this class; secondly, to provide certain improvements in the form of the door, whereby a maximum opening is provided for the passage of fuel through the doorway when 2o the door is open, and, thirdly, to provide certain improvements looking to the more thorough and effective combustion of fuel within the fire-box.

To these ends the invention consists in the a 5 improvements which I will now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification, Figure l represents an end elevation of a locomotive fire-box and 3o boiler embodying my invention. Fig. 2 represents a side elevation of the same. Fig. 3 represents a section on line 3 3 of Fig. 2. Fig. 4 represents a section on line 4 4 of Fig. l. Fig. 5 represents an enlarged section on line 3 5 4 4 of Fig. l looking toward the left. Fig. 6

represents a view similar to Fig. 5, showing the door open. Fig. 7 represents a modification hereinafter referred to. Fig. 8 represents a section on line 8 8 of Fig. 4.

The same reference characters indicate the same parts in Vall'the figures.

In the drawings, ct represents the front or door-containing wall of a locomotive fire-box, said wall in this case containing a waterspace communicating with the water and steam spaces of the boiler.

b represents the fire-door opening, which is preferably formed by the junction of the inner and outer plates of the wall ct, as clearly 5o shown in Figs. 4, 5, and 6, said opening being preferably enlarged 0r ilared at its inner portion and being surrounded by an outwardlyprojecting flange b'. The fire-door is composed of a body portion c, the end portions of which are curved or extended outwardly to form two vertical ears or flanges c' c' at the ends of the body portion. On the outer portions of said flanges and between the upper and lower ends` thereof are located hinged trunnions or pintles d d', said trunnions being preferably formed on or alhxed to the ends of a strap or plate cl2, bolted to the body portion and flanges of the door. The trunnions d d' are journaled in fixed socket-hinge members f f. The arrangement of the hinges thus formed is such that their axes are separated by a considerable distance from the body portion c of the door and are located between the upper and lower edges of the door, so that when the door is opened its lower portion below the hinges is swung inwardly and upwardly,and its upper portion above the hinges is swung downwardly and outwardly, as shown in Fig. 6. An unobstructed opening of considerable height for the passage of fuel below the door is thus provided. The door is formed so that when it is swung downwardly to its closed position (shown in Figs. 4 and 5) its upper and lower edges do not meet the corresponding edges of the dooropening, but are separated therefrom by airpassages extending practically the whole length of the door, the upper end of the door being thus left free to swing downwardly and outwardly. The ends of the door are also preferably separated from the corresponding portions of the door-opening by air-passages. Provision is therefore `made for the constant admission of air in suitable quantity to insure efficient combustion within the fire-box. The air-openingI above the door is considered especially important in connection witha firebrick arch g, which extends from the furnacefront a backwardly into the fire-space above the door-opening, said arch being arranged so that the air admitted above the door impinges against its heated under surface. The arch g is preferably provided with a recess g in its under side and with vertical orifices g2, extending from said recess through the top of the arch. The air entering above the furnacedoor enters the recess g and passes through IOO nions of the door.

the orifices g2, this air becoming highly heat-v ed by contact with the heated surfaces of the arch. Additional supplies of air may be admitted to the arch g by tubular stay-bolts h, extending through the wall a.

i represents another fire-brick arch extending from the opposite end of the fire-box toward the arch g, the two arches being separated by a throat j, through which the products of combustion pass. Air may be admitted to the space above the arches through tubular stay-bolts h'.

The door c is weighted, so that when in its closed position it will be caused to retain said position by gravitation. I have provided yielding retaining means for holding the door in its open position, said means being made operative by the movement of the door to its open position and holding the door yieldingly open, so that it can be readily closed whenever desired.

In the embodiment of my invention shown in`Figs. 5 and 6 the yielding retaining means are as follows: 7.; represents a vertical steamcylinder located below the door at the outer side of the wall a and having a steam-inlet in its upper portion supplied by a steam-pipe la', which may com municate with the steam-space of the boiler and has a valve 7a2, whereby the quantity of steam passing to the cylinder k may be regulated. m represents a piston movable in the cylinder 7.a and located below the steam-inlet thereof, so that the steampressure constantly tends to depress the piston. To the piston is connected a yoke m', the upper end of which is pivotally connected at m2 with a rod or link n. o represents an arm affixed to one of the trunnions of the door c and provided with a slot 0. Said slot receives a pin o2, which connects the upper end of the link n with the arm o. p represents a hand-lever xed to one of the trun- 'lhe arrangement of the arm ois such that when the door is closed, as shown in Fig. 5, the slot 0 is inclined in such direction as to cause the pin o2 to moveto the inner end of the slot. When the pin is in this position, the operative length of the arm or lever 0 is so reduced that the yielding pressure device--that is, the piston m-acted on by the steam-pressure, is not able to overcome the Weight of the door. Consequently the latter remains closed. When the door is opened, as shown in Fig. 6, the arm o assumes an opposite inclination and the pin o2 is caused to move tothe outer end of the slot o.

` The operative length of the lever 0 is thus so tor. In each case the operator grasps the lever p, and through the latter imparts the desired movement to the door. VThe yielding pressure device, instead of being a steampressed piston fm, may be a weight s, adaptedl to slide between guides sV s and suitably connected with the lower end of the rod or link fn, as shown in Fig. 7.

t represents an adjustable stop adapted to limit the opening movement of the door. Said stop, as here shown, is a pin inserted in one of a series of holes t in a fixed segmental arm t2, projecting from the Wall a.

The door is preferably provided on its inner side with an inwardly-projecting iiange or dedector c2, which extends horizontally from end to end of the door and along the inner sides of the curved flanges c. Said rib is arranged to deiect upwardly the current of air that passes over the top of the door when the latter is open or partly open, thus directing the said current into the recess g of the arch g.

I find that the conjoint use of the flange c2 and of the arch g, arranged immediately above the door-opening, so as to act on the air admitted above the door and deiiected upwardly by the flange, enables the steam to be effectively generated when the door is left open or partly open, the air thus admitted being effectively distributed, so that it insures a maximum efficiency of combustion. The hollow staybolts h, arranged to admit air under the arch g, contribute to the result last mentioned.

My invention above described is not limited to tire-boxes of locomotive-engines, but can be applied to the furnaces of other steam boilers or generators.

I claim- 1. In a furnace or fire-box, the combination of a hinged door adapted to open inwardly, and yielding retaining means made operative by the opening of the door to retain the door in its open position, said retaining means being made inoperative by the closing of th door.

2. In a furnace or fire-box, the combination of a hinged door adapted to open inwardly, a yielding pressure device, and changeable connections between the said pressure device and the door, said connections being constructed and arranged to cause the pressure device to overcome the Weight of the door and retain the latter in its open position, and to release the door when the door is moved toward its closed position.

3. In a furnace or fire-box, the combination of a hinged door adapted to open inwardly, a slotted arm affixed to the door, a yielding pressure device, and a rod or link connecting the said device with the slotted arm, the connection between the rod and arm being changeable.

4f. In a furnace or lire-box, the combination of a hinged door adapted to open inwardly, a slotted arm afixed to the door, a steam-cyl- IOL) IIO

nder connected at one end with a source of steam-supply, a piston in said cylinder below the steam-inlet, and connections between the piston and the slotted arm, said connections including a rod or link movably connected with the slotted arm.

5. In a furnace or fire-box, the combination of a hinged door adapted to open inwardly,

yielding retaining means made operative by the opening of the door to retain the door in its open position, said retaining means being made inoperative by the closing of the door, and a lever affixed to the door, whereby the latter may be moved in one direction to make the retaining means operative, and in the opposite direction to cause the weight of the door to overcome the retaining means.

6. In a furnace or fire-box, the combination of a hinged door adapted to open inwardly, yielding retaining means made operative by the opening of the door to retain the door in its open position, and adjustable means for limiting the opening movement of the door.

7. In a furnace or fire-box, the combination of a hinged door adapted to open inwardly, yielding retaining means made operative by the opening of the door to retain the door in its open position, a lever affixed to the door, a segmental arm affixed to the furnace-front and having a series of orifices, and a stop-pin adapted to engage either of said orifices to arrest the outward movement of the lever.

8. In a furnace or fire-box, the combination of a door-casing, a door having outwardlyprojecting ears or anges at its ends and horizontally-arranged hinges connecting the said ears with the furnace-front and arranged with their axes at the outer portions of the ears and between the upper and lower ends of the door, the portion of the door below the hinges being free to swing inwardly and upwardly into the casing, while the upper portion of the door above the hinges is separated from the upper side of the casing by an opening for the admission of air and is free to swing downwardly and outwardly from the casing.

9. In a furnace or fire-box, the combination of an inwardly-opening door formed when closed to be separated from the door-opening, and a fire-brick arch within the fire-box above the door-opening, said arch presenting heated surfaces against which air admitted above the door impinges.

10. In a furnace or frebox,the combination of an inwardly-opening door formed when closed to be separated from the door-opening, a tire-brick arch within the fire-boX above the door-opening, said arch having a recess in its lower side to receive air admitted above the door, and orifices extending from said recess through the arch.

l1. In a furnace or tire-box,the combination of an inwardly-opening door formed when closed to be separated from the door-opening, and two fire-brick arches within the fire-box, said arches extending from opposite ends of the nre-box and being separated by a throat.

12. In a furnace or firebox,the combination of an inwardly-opening door hinged between its upper and lower edges and outside its body portion, said body portion having an air-detlector on its inner side adapted to direct upwardly a current of air passing over the door, and a fire-brick arch within the fireboX above the door-opening andarranged to heat the upwardly-deflected air.

13. In a furnace or fire-box,the combination of an inwardly-opening door adapted to admit air over its upper edge, a fire-brick arch within the fire-box above .the door-opening, and hollow stay-bolts extending through the front wall and arranged to admit air to the under side of the arch.

In testimony whereof I have affixed my signature in presence of two witnesses.

HENRY H. IIUFF.

Witnesses:

C. F. BROWN, E. BATCHELDER. 

